Crankshaft grinding device wheel mount



Nov. 27, 1956 E. A. FUGLIE CRANKSHAFT GRINDING DEVICE WHEEL MOUNT Filed Jan. 10, 1955 Y mmvrox [/we/"fi /Z/g//e BY m Mam HTTORNEUS United States Patent() CRANKSHAFT GRINDING DEVICE WHEEL MOUNT Elmer A. Fuglie, Winona, Minm, assignor to Winona Tool Manufacturing Company, Winona, Minm, a partnership Application January 10, 1955, Serial No. 480,869 3 Claims. (Cl. 51-168) The present invention relates to improvements in the support of the abrasive wheel of a crankshaft grinding device. In general the invention relates to the provision of means for reducing the vibration of a rapidly driven grinding stone, by providing a suitable dust seal and bearing support between a drive shaft and an abrasive grinding stone attached thereto within the interior of the grinding stone.

This application constitutes a continuation-in-part of my prior application Serial No. 371,536, filed July 31, 1953, now Patent 2,700,851, granted February 1, 1955.

In my aforesaid patent there is disclosed a novel connection between the abrasive stone of a crankshaft grinding device and the shaft that drives the stone, consisting of an improved securing head member normally forming a part of the drive shaft and containing an annular opening for receiving one end of a tubular bushing that encompasses the shaft and extends into the annular opening within the head to form a protected bearing between the abrasive member and the drive shaft. The enlarged head member may be formed as an integral part of the driven shaft or it may be separately attached to the shaft. In the present application, I have provided a modification of the invention in the form of a securing member that is bonded to the abrasive stone within a recess therein and is provided with a special opening therein for receiving a portion of the drive shaft as well as a portion of a shaft bushing to form the desired bearing surface within the interior of the abrasive stone. Because the bearing surface is within the interior of the abrasive stone it is protected from the abrasive dust that results from a grinding operation. As the securing member is a relatively small part, and inasmuch as it and the bushing are subject to wear, it is deemed more advisable to make the securing member a permanent part of the abrasive stone so that a new securing member is provided with each stone and is replaceable with the stone.

An object of the invention is to provide an improved connection between the abrasive stone of a crankshaft grinder and the drive shaft that forms with a tubular bushing a dust protected bearing surface between the abrasive stone and the drive shaft.

Another object is to provide in combination with the abrasive stone of a crankshaft grinder having a recess in an axial end thereof, a securing member bonded to the stone within the recess having an axial opening which is partially threaded to receive the threaded end of a drive shaft, and having another portion thereof formed as a larger smooth cylinder adapted to receive a portion of a bushing that encompasses the drive shaft so as to form a dust protected bearing surface within the interior of the stone that cooperates with the drive shaft.

A further object is to provide in combination with a cyindrical abrasive head of a crankshaft grinder having 7 a recess in one axial end thereof, a securing member bonded to the abrasive stone within the recess and having an opening in the axis thereof that contains a first portion that is threaded to receive the threaded end of a drive shaft, 21 second portion conforming with the curvature of a sleeve bonded to the shaft adjacent the threaded end thereof, and a third portion of sutficient diameter to circumscribe a tubular bushing that encompasses the drive shaft so as to form a dust protected bearing between the securing member and the shaft within the interior of the abrasive head.

Other and further objects may become apparent from the following specification and claims, and in the appended drawing in which:

Fig. 1 is a side elevation of a fragmentary portion of a crankshaft grinder, showing portions of the drive shaft, the abrasive stone, and the bushing that extends between the shaft and stone; and,

Fig. 2 is an enlarged vertical section through the grinding stone, bushing and drive shaft shown in Fig. 1.

Referring first to Fig. 1, general reference numeral 10 indicates a fregmentary portion of a crankshaft grinder such as is shown in greater detail in my prior Patents Nos. 2,247,344 and 2,298,055, and in my recently granted Patent 2,700,851.

These devices are provided for grinding the crank pins on the crankshaft of an internal combustion engine, without necessarily removing the crankshaft from the engine. Reference numeral 12 indicates a fragmentary portion of a shaft whose upper end, not shown, supports a yoke that embraces a portion of the crank pin. Reference character 14 indicates a conventional bushing that surrounds rod 12. Surrounding bushing 14 and extending laterally therefrom is an arm structure 16 that supports the grinder assembly, indicated by general reference numeral 18 which is shown in greater detail in Fig. 2 of the drawing.

Referring now to Fig. 2, the grinder assembly 18 is shown in section. It consists of a cylindrical shaped stone 20 formed of bonded abrasive. Within the upper end of stone 20 and extending axially therein is a cylindrical opening 22 which is closed at its inner end. Within the interior of the bottom end of the stone is a larger cylindrical opening 24 that is separated from opening 22 by a partition 26.

Within the interior of the lower opening 24 is an annular member 28 that is relatively broad and shallow and is provided with an outer knurled surface 30 partially shown in Fig. 2. The annular member 28 is firmly held in the recess 24 and in ordinary practice this bond is obtained by the use of molten sulfur, not shown, which is put into the recess before the annular member 28 is inserted therein, and which on cooling expands to form a permanent bond between the stone and the outer knurled surface of the securing member 28.

Withinits interior the securing member 28 is provided with an axial opening of three different dimensions. Within the extreme inner end of the securing member 28 is a threaded opening 32 that extends through the member to the stone partition 26. Spaced outwardly from threaded opening 32 and separated therefrom by a shoulder 36 is a tapered opening 34 in the form of a frustro-conical surface which joins a smooth cylindrical surface 38 that extends through the lower surface of member 28.

A drive shaft 40 that is driven by a motor, not shown, is provided with a short threaded end 42 adapted to be secured in the threaded opening 32 of member 28. A press fit sleeve 44 is provided with an outer tapered surface in the form of a frusto-cone that is adapted to snugly fit within the tapered surface 34 of member 28. Shaft 40 including the threaded end 42 and the press fit sleeve 44 form an integral unit which is readily secured within the securing member 28, and this arrangement provides an annular groove between shaft 40 and the annular portion of securing member 28.

A tubular bushing 48 encompasses the shaft 40 and has its upper end extending into the opening 38 and in abutting relationship with sleeve 44. This provides a first bearing surface 50 between the shaft 40, the securing member 28 and the sleeve 44' which is within the interior stone 20 thereby providing a relatively dust free seal within the interior of the stone. Bushing 43 also provides an exterior bearing surface 52 with the arm 16 as seen in Fig. l.

Having reference to Fig. 2 it will be evident that by virtue of the broad shallow connection between the drive shaft 40 and the stone 20, that a relatively large portion of the stone may be used for grinding purposes thereby effecting a substantial economy in the usable portion of the stone.

While some economic advantage-is gained through the invention by providing a connection between the drive shaft and the stone that is realtively shallow and permits using a greater proportion of the grinding stone than has been heretofore possible, the principal advantage resides in the provision of a dust sealed bearing within the interior of the abrasive stone. It will be appreciated that in performing a grinding operation on a crankshaft, the dust arising therefrom will include particles of steel as well as particles of the abrasive material, both of which can cause serious injury to any bearing surface. However, because these particles are relatively large in size, and a multiple sealing surface is provided between the various portions of the drive shaft and the stone, theinvention completely protects these surfaces. Moreover, the gen-: eral arrangement of the invention provides a novel mounting that eliminates vibration of the outer end of the drive shaft.

It is to be understood that the construction shown and described are merely for illustration and that various changes in size, shape and arrangement of parts may be made without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In a device of the class described, in combination, a circular bonded abrasive grinding stone formed with=a relatively broad axial recess therein, a securing member bonded to the stone within said recess, said member con taining an axial opening extending inwardly within the interior of the stone, the innermost portion ofsaid .opening formed with'an internal spiral thread, the outer portion of said opening formed as a smooth circular surface of greater diameter than saidzinnermost threadedportion, a drive shaft formed with'azthreaded' outer end. adapted for securing in the threaded innermost portion of said securing member, a sleeve'aofv greater diameterrthan the shaft securely fitted on said shaft in rear of the. threaded end thereof that closely engages apartof the outerportion of the openingin. said securing. member, a supporting member, and a tubular bushing encompassing the shaft with one end forming a bearing between the supperting member and the shaft, and the other end projecting into the opening of the securing member and abutting said sleeve forming a dust-tight seal and bearing within the interior of the sleeve to eliminate vibration on the outer end of the shaft.

2. In a crankshaft grinder, a drive shaft formed with a threaded outer end; atsleeveof greater diameter than the shaft securely fitted on the shaft in rear of. the threaded end thereof, a cylindricalbonded abrasive grinding stone formed with a relatively broad recess in one axialend thereof, a securing member bonded: to the stone within said. recess, said member containing an axial opening extending inwardly within the interior of the stone, the inner portion of said opening laterally threaded to receive the threaded end of the drive shaft, the outer portion of said opening formed asa smooth cylinder of greater diameter than the drive shaft,-an intermediary portion of said opening formed in the same contour as the sleeve on the shaft to embrace the sleeve, and a tubular bushing encompassing the shaft and extending inwardly into the opening of said securing member to form a dust protected-bearingsurface between the sleev'e', the securing member and the drive shaft within the interior of the abrasive stone.

3. In a crankshaft grinder, adrive shaft formed with a threaded outer end, a sleeve securely fittedon the shaft'adiacent thethreaded end thereof, theouter surface of-said sleeve tapered as a frusto-cone tapering in the direction of the'threaded endof the shaft, a cylindrical bonded abrasive grinding stonezformed with a -relativelybroad recess inone end thereof, a securingi member bondedlto the stone. within the:said recess, said member containing an axial opening.extendinginwardly within the interior of the stone, the inner; portion. of said opening laterally threaded to receive'the threaded end of the drive shaft, the outer portion of said opening forme'd as-a smooth cylinder. of greater diameter than: the drive shaft, an intermediary portion of saidopeninglformed as a tapered frusto-coneto-snuglyfit about: thesleeve on the shaft, and a tubular bushing encompassing-said shaft and'extending into'the smooth cylindrical. portion'of the opening of said securing. member to formra dust protected bearing surface between:the securing member and the drive shaft within theinteriorof the abrasive' stone.

References Cited in the file-of this :patent UNITED STATES PATENTS 

